I've read the note on Magpul's site and wanted to know if anyone actually got their MBUS front sight to melt from being used on a high gas block?



An oklahomashooter website had a thread where someone used an IR thermometer to measure the heat from the gas block and it was 220F. That's not hot at all considering most modern engines utilize polymer intake manifolds and other plastic parts directly in contact with engine blocks and cylinder heads. These engine blocks and heads are rated well above 220F and the plastics don't smoke/smolder/melt. Ford uses Dupont Zytel Nylon for the intake manifolds. What does Magpul use for their MBUS, PMags, furniture, etc??



The standard CAR/M4/AR/M16 handguards are in direct contact with the front-sight block/handguard retainer and it takes a lot of rapid firing to get them to even smoke.



I guess my question is, has anyone actually seen a MBUS front sight melt when used on a gas block? Or is this a "it might happen" kind of deal?

I have never seen one melt! And I've seen some barrels literally smoking because so many rounds had been run through it! Never any issues with heat and definitely no melting as a result of extreme heat!  They're good to go!

I have not seen a melted one yet but I was thinking about trying this just to see how long it would last. The other problem is I think there would be a height problem.

I know a lot of people cite the height issue, but there are tall gas blocks available, along with the CMMG/AA piston gas blocks that are level with the upper receiver rail.